1. Field of Invention
The present invention relates to the field of optics to precede the hidden image product and its recognition, and more particularly to a hidden image identification system and the producing method thereof for providing a hidden image information of a product.
2. Description of Related Arts
In the existing identification technology, the overwhelming major method utilizes the other products (the third supplies) to distinguish the identity of the products, such as mark sticker, radiation frequency mark (RFID), barcode, code, telecom code technology, packaging of products, database, special craft, supplies, color, sizes, name, and type. These marks can be identified by observation through the eye of a user, so that the marks can be easily copied. In other words, the anti-falsification of these marks is bad. On the other hand, some of the marks may need the special-purpose or expensive testing tools to identify them, so the identification process is inconvenient, high costs, and difficult to popularize.
A good recognition and anti-falsification technology needs to meet the following condition: The technology has low processing costs, low measuring costs, precise testing messages, difficult to copy, no influence the appearance and production procedure, able to cooperate the procedure of processing, convenient to measure, traceability, uniqueness, anti-falsification function, products' compatibility, management ability, self-technology protecting, and so on.
In order to accomplish the above function, the technology is the most important matter. The technology can't depend on new supplies, tedious processing procedure or craft. It should avoid the complicated and expensive electronic detecting instrument. It should adopt a kind of technology that can join in the process of production, and does not need other processing. The most ideal method is to depend on the essential and superficial lamination structure of the supplies or printing site structure to distinguish, and which is equal with biological fingerprint, pupil, etc.
The existing hidden image recognition technologies all have the insufficient precision problems and cannot use the naked eyes to distinguish. They can be tested with specific recognizer, the lens, and the grating materials which can buy on the market. The testing images are ambiguous, like the secret mark. Further, the structure of the image is single, and the accurate of density is usually only at 200 line/inch or 80 line/centimeter. This technology cannot satisfy with the recognition and safe requirement of anti-falsification.
Furthermore, the existing hidden image technology usually takes advantage of the features of the optical grating because the hidden image is composed by a plurality of dots. Therefore, the hidden image can only be printed on a printing paper, and is hardly use on the product directly. Otherwise, the hidden image being directly printed on the product may damage the appearance to the product. The existing optical grating is only focus on the application of the 3-dimensional optical grating, but neglecting the importance of anti-falsification and safe identification. Its highest level of optical grating can only below 159 lines per inch or 63 lines per centimeter. Therefore, the format is too easy for the imitator to copy the product. Finally, it is obviously can't achieve the requirement of the recognition and safe requirement of anti-falsification.